A powered tool is a tool that is actuated by an additional power source and mechanism other than the solely manual labor used with hand tools. The most common types of powered tools use electric motors. Internal combustion engines and compressed air are also commonly used. Other power sources include steam engines, direct burning of fuels and propellants or even natural power sources like wind or moving water. Powered tools are used in industry, in construction and/or manufacturing for purposes of, for example, driving fasteners, drilling, cutting, shaping, sanding, grinding, routing, polishing, painting, heating and more. Powered tools are classified as either stationary or portable, where portable means hand-held. Portable powered tools have advantages in mobility. Stationary power tools however often have advantages in speed and accuracy and some stationary powered tools can produce objects that cannot be made in any other way. A drill is a type of powered tool fitted with a cutting tool attachment or driving tool attachment, usually a drill bit or driver bit, used for drilling holes in various materials or for fastening various materials together with the use of fasteners.
A fastener is a hardware device that mechanically joins or affixes two or more objects together. A screw, or bolt, is a type of fastener characterized by a helical ridge, known as an external thread or just thread, wrapped around a cylinder. Some screw threads are designed to mate with a complementary thread, known as an internal thread, often in the form of a nut or an object that has the internal thread formed into it. Other screw threads are designed to cut a helical groove in a softer material as the screw is inserted. The most common uses of screws are to hold objects together and to position objects.